> 29.11.2011 12:35, Vlad Khorsun wrote:
>
>> While i agree with you about SUBSTRING, i think the much better solution
>> will be to allow to index COMPUTED BY columns. It allows to not compare
>> potentially complex expressions at optimize time and to not write exactly
>> same expressions in every query where such index is required.
>
> Perhaps. And we have such a request in the tracker, AFAIR.
>
> I'm just not really sure that adding a dummy column (that could never be
> selected from explicitly) to improve the performance looks like a proper
> approach.
While it will not be present in SELECT list, it will be used in WHERE
clause, so i'd not call it dummy ;)
> Surely computed columns don't add any extra overhead unless
> you select * from the table, but this still doesn't look elegant, IMHO.
> But that's just me, I'm not going to object seriously.
With 64KB limitation on record size it could be a problem, agree...
Regards,
Vlad
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